Systems and methods for interactive control of window/level parameters of multi-image displays

ABSTRACT

A technology enables interactive control of simultaneously displayed multiple images with high dynamic ranges, which software automation processes are programmed to reduce the complexity in managing and viewing the post window/level adjustment of the multiple images. An image control engine provides several synchronous functional capabilities, which comprises an input module, a blending factor synchronization module, a window/level synchronization module, a display module, and an image storage. For window/level adjustment of the images in blended views, the blending factor synchronization module automatically links the activation of a window/level control of one image with a transparency blending factor that affects both images. For synchronization of window/level adjustments of two or more images, a window/level synchronization module is configured to automatically change window/level parameters of all remaining images when the user makes an adjustment to a window/level control of one image such that all images with updated window/level parameters are displayed simultaneously.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/405,353, filed on Feb. 26, 2012, which claims benefit of U.S.Provisional Patent Application Ser. No. 61/447,667, filed on Feb. 28,2011, all of which are incorporated by reference herein for allpurposes.

This application is related to U.S. patent application Ser. No.12/821,977, filed Jun. 23, 2010, U.S. patent application Ser. No.12/821,985 filed Jun. 23, 2010, and U.S. patent application Ser. No.12/925,663 filed Oct. 27, 2010, which are incorporated by referenceherein for all purposes.

TECHNICAL FIELD

The present invention relates generally to medical imaging processing,and more particularly to interactive control of window/level adjustmentsof multiple images when displaying images simultaneously or in a blendedview.

BACKGROUND

Medical image scanners like x-ray, computerized tomography (CT), conebeam computerized tomography (CBCT), magnetic resonance imaging (MRI),positron emission tomography (PET), or ultrasound typically acquire rawintensity values in a very high dynamic range. For instance, severalcommercially available computed tomography scanners are able to cover arange of about 4,000 different intensities. This high dynamic range isusually too large to fit most display devices. It is practical,therefore, to map the high dynamic range to a smaller intensityinterval, such as the 256 different gray-scale values of a typicalcomputer monitor. This can be accomplished by choosing a continuousrange of interest out of the full input intensity range by setting twoparameters: the width of the range, also referred to as “window,” andthe center of the range, also referred to as “level.” For displaying animage, all input intensities within that range are then continuouslymapped to the full range of output intensities. Input intensities belowand above that range are mapped to the minimal and maximal outputintensities. This mapping technique is not only employed to address theabove-mentioned described technical limitations of display devices butalso factors in that the human eye is not sufficiently sensitive todifferentiate between all input intensities. Choosing a small intensitywindow allows for enhancing image contrast in a specific range ofinterest while masking out all other intensities that may not containrelevant information. The output from the described mapping technique isnot constrained to gray scale values. The intensity window can alsoestablish a mapping between the input values and a user-defined colormap.

Several different approaches are possible in selecting suitable windowand level parameters. Various algorithms have been developed fordetermining those values automatically based on image content, displayproperties, and a desired case. However, most display systemsadditionally include tools for setting those values manually, e.g. byentering numbers or by moving sliders, for situations where an automaticalgorithm is not able to produce the target result.

Accordingly, it is desirable to have a system and method for simplifyingthe manual window/level adjustments in the simultaneous display of twoor more images for medical image applications and instrumentations.

SUMMARY

The present invention is directed to a method, system, and article ofmanufacture for interactive control of multiple images with a highdynamic range that are displayed simultaneously for which softwareautomation processes are programmed to reduce the complexity in managingand viewing the post window/level adjustment of the multiple images. Amedical image control engine is configured to provide severalsynchronous functional capabilities, which comprises an input module, ablending factor synchronization module, a window/level synchronizationmodule, a display module, and an image storage. In a first scenario withwindow/level adjustment of two images in blended views where two imagesare displayed as semi-transparent overlays, the blending factorsynchronization module is configured to automatically link theactivation of a window/level control of one image with a transparencyblending factor that affects both images. In radiotherapy, such viewsare for example used for patient positioning. At the beginning of eachtreatment fraction, the patient is positioned at the treatment machineand a CBCT is acquired. This image is displayed in a blended viewtogether with the initial CT that has been used for treatment planningThe deviations between the two images are then used for correcting thepatient's position to comply with the treatment plan. In a secondscenario with synchronization of window/level adjustments of two or moreimages, a window/level synchronization module is configured toautomatically change window/level parameters of all remaining imageswhen the user makes an adjustment to a window/level control of one imagesuch that all images with updated window/level parameters are displayedsimultaneously, or substantially simultaneously. In the radiotherapyexample this can be used to display all positioning CBCTs side by sidefor visualizing tumor progression over treatment time.

In a first aspect of the invention, the medical image control engine isconfigured to automatically adjust the degree of transparency of anon-affected image in response to a deliberate action to interact withthe window/level control of an affected image. The affected imagebecomes fully opaque while the non-affected image becomes fullytransparent so that the affected image is capable of shining through thenon-affected image. In a blended view of two images, the transparency ofone image has an inverse relationship with the transparency of anotherimage, such that when one image is fully opaque, the other image isfully transparent. The activation of the window/level controls of anaffected image is linked to the movement of the transparency blendingfactor so that the interaction with the window/level controls of theaffected image automatically causes the transparency blending factor toslide all the way in one direction. If the user selects to adjust thewindow/level parameters of the first image, the first image becomesfully opaque because the transparent blending factor is at 0% for thefirst image while the second image becomes fully transparent because thetransparent blending factor is at 100% for the second image. If the userselects to adjust the window/level parameters of the second image, thesecond image becomes fully opaque because the transparent blendingfactor is at 0% for the second image while the first image becomes fullytransparent because the transparent blending factor is at 100% for thefirst image. The transparency state is retained so long as the user isinteracting with the window/level control of the first image or thewindow/level control of the second image. The degree of transparencyblending factor is reset to its original value after the user hasfinished interacting with the window/level control associated with aparticular image.

In a second aspect of the invention, the medical image control engine isconfigured to provide a synchronous interactive modification of thewindow/level parameters for multiple images. When the user interactswith the window/level control associated with a particular image, thewindow/level synchronization module not only adjusts the window/levelparameters of that image, but also propagates the changes to all otherimages. As a result, all image views and window/level parameters areautomatically updated. If the system displays N images, when thewindow/level parameters to one of the N images are adjusted (theselected image), the system executes the N−1 synchronization mechanismsto the unselected images (a sum of N−1 images). Such a synchronizationmechanism can be implemented using in a wide variety of techniques, e.g.a general mapping method, a pass-through method, and a histogramequalization method.

Broadly stated, a computer-implemented method for adjusting a pluralityof images comprises: displaying a first image and a second image in ablended view on a display, the first image associated with firstwindow/level parameters and the second image associated with secondwindow/level parameters; adjusting the first window/level parameters ofthe first image thereby causing a transparency blending factor to changeto a first value; and displaying the first and second images in theblended view on the display based on the adjustments to the firstwindow/level parameters and the transparency blending factor.

The present invention provides a method to effectively automate thedisplay of two medical images when a user adjusts the window/level ofone image without the need to manually adjust the transparency blendingfactor.

The structures and methods of the present invention are disclosed in thedetailed description below. This summary does not purport to define theinvention. The invention is defined by the claims. These and otherembodiments, features, aspects, and advantages of the invention willbecome better understood with regard to the following description,appended claims, and accompanying drawings.

DESCRIPTION OF THE DRAWINGS

The invention will be described with respect to specific embodimentsthereof, and reference will be made to the drawings, in which:

FIG. 1 is a block diagram illustrating a first system embodiment of anexemplary interactive computer system for adjusting window/levelparameters of multiple image displays in accordance with the presentinvention.

FIG. 2 is a block diagram illustrating an exemplary multi-image controlengine in accordance with the present invention.

FIG. 3 is a screen shot illustrating a window/level adjustment platformof the images in a blended view without any window/level adjustment inaccordance with the present invention.

FIG. 4A is a pictorial diagram illustrating a blending image view withwindow/level and blending factor controls in accordance with the presentinvention; FIG. 4B is a pictorial diagram illustrating a blending imageview with the blending factor set to zero in accordance with the presentinvention; and FIG. 4C is a pictorial diagram illustrating a blendingimage view with the blending factor set to one in accordance with thepresent invention.

FIG. 5 is a screen shot illustrating a window/level adjustment of afirst image on the blended-image display with respect to FIG. 3 inaccordance with the present invention.

FIG. 6 is a screen shot illustrating a window/level adjustment of asecond image on the blended-image display with respect to FIG. 3 inaccordance with the present invention.

FIG. 7 is a flow diagram illustrating an exemplary process for executinga window/level adjustment in blended views in accordance with thepresent invention.

FIG. 8 is a flow diagram illustrating the process for executing asynchronized window/level adjustment of multiple images in accordancewith the present invention.

FIG. 9A is a block diagram illustrating a first embodiment of a generalmapping method for executing a synchronized window/level adjustment ofmultiple images in accordance with the present invention; FIG. 9B is ablock diagram illustrating a second embodiment of a pass-through methodfor executing a synchronized window/level adjustment of multiple imagesin accordance with the present invention; and FIG. 9C is a block diagramillustrating a third embodiment of a histogram equalization method forexecuting a synchronized window/level adjustment of multiple images asdescribed in FIG. 8 in accordance with the present invention.

FIG. 10 is a flow diagram illustrating an exemplary histogramequalization process for executing a synchronized window/leveladjustment of multiple images in accordance with the present invention.

FIG. 11 is a block diagram illustrating a second system embodiment of acloud computing environment accessible by cloud clients for a physicianto view and adjust window/level parameters of multiple image displays inaccordance with the present invention.

DETAILED DESCRIPTION

A description of structural embodiments and methods of the presentinvention is provided with reference to FIGS. 1-11. It is to beunderstood that there is no intention to limit the invention to thespecifically disclosed embodiments but that the invention may bepracticed using other features, elements, methods, and embodiments. Likeelements in various embodiments are commonly referred to with likereference numerals.

FIG. 1 is a block diagram that illustrates an exemplary interactivecomputer system for adjusting window/level parameters of multiple imagedisplays upon which a system embodiment of the invention may beimplemented. A computer system 10 includes a processor 12 for processinginformation, and the processor 12 is coupled to a bus 14 or othercommunication medium for sending and receiving information. Theprocessor 12 may be an example of the processor 12 of FIG. 1, or anotherprocessor that is used to perform various functions described herein. Insome cases, the computer system 10 may be used to implement theprocessor 12 as a system-on-a-chip integrated circuit. The computersystem 10 also includes a main memory 16, such as a random access memory(RAM) or other dynamic storage device, coupled to the bus 14 for storinginformation and instructions to be executed by the processor 12. Themain memory 16 also may be used for storing temporary variables or otherintermediate information during execution of instructions by theprocessor 12. The computer system 10 further includes a read only memory(ROM) 18 or other static storage device coupled to the bus 14 forstoring static information and instructions for the processor 12. A datastorage device 20, such as a magnetic disk (e.g., a hard disk drive), anoptical disk, or a flash memory, is provided and coupled to the bus 14for storing information and instructions. The computer system 10 (e.g.,desktops, laptops, tablets) may operate on any operating system platformusing Windows® by Microsoft Corporation, MacOS or iOS by Apple, Inc.,Linux, UNIX, and/or Android by Google Inc.

The computer system 10 may be coupled via the bus 14 to a display 22,such as a flat panel for displaying information to a user. An inputdevice 24, including alphanumeric, pen or finger touchscreen input, andother keys, is coupled to the bus 14 for communicating information andcommand selections to the processor 12. Another type of user inputdevice is cursor control 26, such as a mouse (either wired or wireless),a trackball, a laser remote mouse control, or cursor direction keys forcommunicating direction information and command selections to theprocessor 12 and for controlling cursor movement on the display 22. Thisinput device typically has two degrees of freedom in two axes, a firstaxis (e.g., x) and a second axis (e.g., y), that allows the device tospecify positions in a plane.

The computer system 10 may be used for performing various functions(e.g., calculation) in accordance with the embodiments described herein.According to one embodiment, such use is provided by the computer system10 in response to the processor 12 executing one or more sequences ofone or more instructions contained in the main memory 16. Suchinstructions may be read into the main memory 16 from anothercomputer-readable medium, such as storage device 20. Execution of thesequences of instructions contained in the main memory 16 causes theprocessor 12 to perform the process steps described herein. One or moreprocessors in a multi-processing arrangement may also be employed toexecute the sequences of instructions contained in the main memory 16.In alternative embodiments, hard-wired circuitry may be used in place ofor in combination with software instructions to implement the invention.Thus, embodiments of the invention are not limited to any specificcombination of hardware circuitry and software.

The term “computer-readable medium” as used herein refers to any mediumthat participates in providing instructions to the processor 12 forexecution. Common forms of computer-readable media include, but are notlimited to, non-volatile media, volatile media, transmission media, afloppy disk, a flexible disk, a hard disk, magnetic tape, any othermagnetic medium, a CD-ROM, a DVD, a Blu-ray Disc, any other opticalmedium, punch cards, paper tape, any other physical medium with patternsof holes, a RAM, a PROM, an EPROM, a FLASH-EPROM, any other memory chipor cartridge, a carrier wave as described hereinafter, or any othermedium from which a computer can read. Non-volatile media includes, forexample, optical or magnetic disks, such as the storage device 20.Volatile media includes dynamic memory, such as the main memory 16.Transmission media includes coaxial cables, copper wire, and fiberoptics. Transmission media can also take the form of acoustic or lightwaves, such as those generated during radio wave and infrared datacommunications.

Various forms of computer-readable media may be involved in carrying oneor more sequences of one or more instructions to the processor 12 forexecution. For example, the instructions may initially be carried on amagnetic disk of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over acommunication link 28. The computer system 10 includes a communicationinterface 30 for receiving the data on the communication link 28. Thebus 14 carries the data to the main memory 16, from which the processor12 retrieves and executes the instructions. The instructions received bythe main memory 16 may optionally be stored on the storage device 20either before or after execution by the processor 12.

The communication interface 30, which is coupled to the bus 14, providesa two-way data communication coupling to the network link 28 that isconnected to a communication network 32. For example, the communicationinterface 30 may be implemented in a variety of ways, such as anintegrated services digital network (ISDN), a local area network (LAN)card to provide a data communication connection to a compatible LAN, aWireless Local Area Network (WLAN) and Wide Area Network (WAN),Bluetooth, and a cellular data network (e.g. 3G, 4G). In wireless links,the communication interface 30 sends and receives electrical,electromagnetic or optical signals that carry data streams representingvarious types of information.

The communication link 28 typically provides data communication throughone or more networks to other devices. For example, the communicationlink 28 may provide a connection through the communication network 32 toa medical equipment 34 such as an x-ray scanner, a CT scanner, a CBCTscanner, an MRI scanner, a PET scanner, an ultrasound scanner, or animage archive such as a PACS system. The image data streams transportedover the communication link 28 can comprise electrical, electromagneticor optical signals. The signals through the various networks and thesignals on the communication link 28 and through the communicationinterface 30, which carry data to and from the computer system 10, areexemplary forms of carrier waves transporting the information. Thecomputer system 10 can send messages and receive data, including imagefiles and program code, through the network 32, the communication link28, and the communication interface 30.

Alternatively, image files can be transported manually through aportable storage device like a USB flash drive for loading into thestorage device 20 or main memory 16 of the computer system 10, withoutnecessarily transmitting the image files to the communication interface30 via the network 32 and the communication link 28.

FIG. 2 is a block diagram illustrating an exemplary medical imagecontrol engine 36 that includes a blending factor synchronization module38 and a window/level synchronization module 40. The medical imagecontrol engine 36 also includes an input module 42 and a display module50, where the input module 42 contains an image selection component 44,a window/level input component 46, and a blending factor input component48, and the display module 50 contains a window/level component 52, animage display component 54, and an image storage 56. In a standard imagedisplay, the user selects an image using the image selection component44. The selected image is then loaded from the image storage 56 andtransmitted to a window/level module component 52. The window/levelcomponent 52 is configured to convert the raw pixel intensities todisplay intensities using the parameters from the window/level input 46.The image display component 54 then displays the converted intensitieson the display 22. In one embodiment, the medical image control engine36 resides in the RAM memory 16 executable by the processor 12. Inanother embodiment, the medical image control engine 36, implementedeither in software or hardware, that is stored or designed in thenon-volatile memory 18 for loading and execution by the processor 12.

Optionally, the user may display multiple images at the same time. Insuch a case, there are multiple instances of the window/level inputcomponents 46, the window/level components 52, and the image display 56.If the user chooses to display multiple images in a blended view, theblending factor input component 48 can be configured to adjust the imagetransparencies.

The blending factor synchronization module 38 and the window/levelsynchronization module 40 are configured on the memory 16 for operationby simulating one or more user inputs. If the user adjusts one specificcontrol, other controls in the input module 42 adjust automatically,which subsequently leads to updates in the display module 50.

In one embodiment, described as a blending factor synchronization with ablended view, the blending factor synchronization module 38 isconfigured on the memory 16 to detect whenever the user manipulates awindow/level input control. As soon as this happens, the blending factorsynchronization module 38 is configured on the memory 16 to adjust theblending input control to fully display one single image in a blendedview. When the user stops using the window/level input 46, the blendingfactor control is reset again to its previous (or original) state.

In another embodiment, described as a window/level synchronization witha multi-image display, the user may activate the window/levelsynchronization module 40. The window/level synchronization module 40 isconfigured to receive manual changes made in one of the multiplewindow/level inputs 46. The window/level synchronization module 40 isconfigured to correspondingly adjust all other window/level inputs 46 tocorrelative values in which all images are displayed with correspondingbrightness and contrast. Depending on the algorithm, the window/levelsynchronization module 40 may need to obtain data from other modules.For example, the histogram equalization routine is dependent on theconverted image intensities coming from the window/level applicationcomponent 52. More general algorithms may need more data such as imagemetadata from the image storage 56. The simple pass-through algorithm onthe other hand does not depend on any data besides the inputwindow/level parameters.

It will readily be appreciated by one of ordinary skill in the art thatthere are multiple possible combinations for the herein describedcomponent applications and modules. For example, the blending factorsynchronization module and window/level synchronization module may alsofunction as a standalone application, separate from the image storage56. Although the medical image control engine 36 is described as beingcomprised of various components (e.g., the input module 42, the blendingfactor synchronization module 38, the window/level synchronizationmodule 40, the display module 50, and the image storage 56), fewer ormore components may comprise the medical image control engine 36 andstill fall within the scope of various embodiments.

FIG. 3 is a screen shot 58 illustrating a window/level adjustmentplatform of images 60, 62 (also referred to as “first medical image” or“image A,” and “second medical image” or “image B”) in a blended view 64without any window/level adjustment. One embodiment of the images 60, 62refers to medical images captured by the medical equipment 34. Thepresent invention is not limited to medical images, but other images arealso applicable, such as photographs. An example of a medical image iscaptured by a CT scanner that emits radiation toward a patient to beimaged. CT scanning is used in a variety of medical fields, such as inradiology, cardiology, and oncology, to diagnose conditions anddiseases, as well as to plan radiation treatments.

In blended views, two images 60, 62 are present at the same time thatshowing both images 60, 62 semi-transparently overlaid on top of eachother. In this illustration, a CT scanner is used to capture the firstmedical image 60 and the second medical image 62. The first medicalimage 60 and the second medical image 62 are often not exactly alignedto one another, as is the case here, due in part to a patient'sorientation and position on a table and the sampling geometry of the CTscanner. By observing the edges of the medical images 60, 62, the firstmedical image 60 has a northward geometry boundary that extends abovethe second medical image, as well as portions in the southwest directionand the cast direction.

The degree of transparency can be chosen continuously between a value of0, where the first medical image 60 is fully opaque while the secondmedical image 62 is fully transparent, and a value of 1, where the firstmedical image 60 is fully transparent while the second medical image 62is fully opaque. A transparency slider 66 (also referred to as“transparency blending factor” or “blending factor”) has a pointer 68 toindicate the degree of the transparency. When the pointer 68 is movedcompletely toward the left end of the transparency slider 66, the firstmedical image 60 is shown and the second medical image 62 is not shown.A sample illustration utilizing the same principle as the invention butwith an image character content rather than an image from a patient isshown in FIG. 4A. An alphabet letter A 76 represents the first medicalimage 60 and an alphabet letter B 78 represents the second medical image62. The alphabet letter A 76 is completely opaque while the alphabetletter B 78 is completely transparent. When the pointer 68 is movedcompletely toward the right end of the transparency slider 66, thesecond medical image 62 is shown and the first medical image 62 is notshown. In the sample illustration in FIG. 4B, the alphabet letter B 78is completely opaque while the alphabet letter A 76 is completelytransparent. If the pointer 68 is placed in the middle of thetransparency slider 66, which has a value of 0.5, both the first medicalimage 60 and the second medical image 62 are shown with the same 50%transparency. As illustrated in FIG. 4C, both the alphabet letter A 76and the alphabet letter B 78 are shown, but each of the alphabet lettersA 76 and B 78 is 50% transparent and 50% opaque.

The window/level parameters for the first medical image 60 and thesecond medical image 62 can be chosen separately. To provide thisfunctionality, the user interface has to contain two controls 70, 72 forthat purpose, the first window/level control 70 adjusting thewindow/level of the first medical image 60 and the second window/levelcontrol 72 adjusting the window/level of the second medical image 62.The first window/level control 70 is linked to the transparency slider66 and has a corresponding functional relationship with the transparencyslider 66. When a mouse cursor 74 moves the first window/level control70 of the first medical image 60, the transparency slider 66 is adjustedautomatically and proportionally so that the affected image (i.e., thefirst medical image 60) becomes completely opaque and the non-affectedimage (i.e., the second medical image 62) becomes completelytransparent. Similarly, the second window/level control 72 is linked tothe transparency slider 66 and has a corresponding functionalrelationship with the transparency slider 66. When the mouse cursor 74moves the second window/level control 72 of the second medical image 62,the transparency slider 66 is adjusted automatically and proportionallyso that the affected image (i.e., the second medical image 62) becomescompletely opaque and the non-affected image (i.e., the first medicalimage 60), becomes completely transparent.

The term “automatic adjustment” is broadly construed to include, but notbe limited to, either of the following definitions: once initiated by awindow/level control, the transparency function of the images isperformed by a machine, without the need for manually performing thefunction; in a manner that, once begun, is largely or completely withouthuman assistance.

Various embodiments are possible in determining a start action and anend action of the window/level interaction. In one embodiment, the mousecursor 74 (also referred to as “mouse pointer 74”) is used to interactwith the window/level parameters which are based on the position of themouse pointer 74. As soon as the mouse pointer 74 enters the area of thefirst window/level control region 70 or the second window/level controlregion 72, the transparency blending factor 66 is adjustedproportionally. As soon as the mouse pointer 74 leaves the area of thefirst window/level control region 70 or the second window/level controlregion 72, the transparency blending factor 66 is reset to its originalvalue (or a predetermined value). The process of adjusting and resettingthe transparency blending factor 66 can be done in two ways: the factorcan change either instantaneously or more slowly during an animatedtransition phase. The latter makes it easier for the user to understandthe full concept.

FIG. 5 is a screen shot 80 illustrating a composite blended view 82 witha window/level adjustment of the first medical image 60 with respect toFIG. 3. The mouse cursor 74 is pointed at the first window/level control70 to a position which automatically causes the pointer 68 to move allthe way to the left to produce the transparency factor 66 of 0%. As aresult, the composite blended view 82 shows the first medical image 60to be completely opaque and the second medical image 62 to be completelytransparent. The pointing of the mouse cursor 74 to the firstwindow/level control 70 affects the first medical image 62 but does notaffect the second medical image 62. With the act of placing the mousecursor 74 to the first window/level control region 70 to change thewindow/level values, the blending factor synchronization module 38automatically adjusts the pointer 68 on the transparency slider 66 todisplay the blended view 82 showing the first medical image 60 as beingfully opaque and the second medical image 62 as being fully transparent.The mouse cursor 74 is intended as an example of an input device foradjusting the window/level controls 70, 72. Other forms of input devicesare also operable with the present invention, such as an alphanumerickeyboard, in which alphanumeric keys can indicate the variousfunctionalities that parallel the pointer movement of the mouse cursor74 for changing the parameters of the window/level controls 70, 72associated with the first medical image 60 and the second medical image62, respectively.

FIG. 6 is a screen shot 84 illustrating a composite blended view 86 witha window/level adjustment of the second medical image 62 with respect toFIG. 3. The mouse cursor 74 is pointed at the second window/levelcontrol 72 to a position which automatically causes the pointer 68 tomove all the way to the right to produce the transparency factor 66 of100%. As a result, the composite blended view 86 shows the secondmedical image 62 to be completely opaque and the first medical image 60to be completely transparent. Pointing the mouse cursor 74 to the secondwindow/level control 72 affects the second medical image 62 but does notaffect the first medical image 60. With the act of placing the mousecursor 74 to the second window/level control region 72 to change thewindow/level values, the blending factor synchronization module 38automatically adjusts the pointer 68 on the transparency slider 66 todisplay the blended view 86 showing the second medical image 62 as beingfully opaque and the first medical image 60 as being fully transparent.

The first window/level control 70 and the second window/level control 72in the illustrated embodiment are implemented by visually displaying thefirst window/level control 70 as a first slider on the left side of theimages 60, 62 and the second window/level control 72 as a second slideron the right side of the images 60, 62. The first and secondwindow/level controls 70, 72 for adjusting the window/level do not haveto be sliders. In some embodiments, other suitable controls such as anumerical input or dials can be used to function as the window/levelcontrols. In some embodiments, the window/level controls can just beidentified areas or a particular region (crop or a sub-region selectableby user) that represent certain portions on the display 22, such as aleft area of the images 60, 62 (or different quadrants) on the display11 and the right area of the images 60, 62 on the display 22 without anyadditional visual indication. These identified areas on the display 22can be invisible (also referred to as invisible visually), but the useris able to move the mouse cursor 74 within a particular identified areaor region on the display 22 to activate a window/level control that isassociated with the particular identified area by, for example, clickingon the mouse cursor 74, for making transparency or opaqueness adjustmentas described in the present invention. The user may change thewindow/level parameters by, for example, pressing and holding one mousebutton and moving the mouse, in a horizontal motion or a verticalmotion, within such an area.

It is contemplated within the present invention to combine additionalfunctional features with the transparency adjustment. One example is tocombine a zooming function with a transparency function, and apply thezooming/transparency (also referred to zooming+transparency) combinationto a particular region or sub-region. Implementation of suchcombinational zooming/transparency feature can be carried out in avariety of methods. In one approach, when the user moves the mousecursor 74 within a particular sub-region (or a particular region) of anmedical image (either the first medical image 60 or the second medicalimage 62) to activate a window/level control associated with theparticular sub-region of the medical image, the particular sub-region ofthe medical image becomes more fully transparent and the zooming factorincreases simultaneously, resulting in a higher transparent and close-upview of the medical image. To phrase it as a method concept, theblending factor synchronization module 38 is configured to perform thezooming/transparency function to a particular sub-region on the firstmedical image 60 or the second medical image 62.

FIG. 7 is a flow diagram 88 illustrating an exemplary process forexecuting a window/level adjustment in blended views. At step 90, theuser views the first medical image 60 and the second medical image 62,and adjusts the transparency blending factor 66 to a value that the userprefers. The processor 12, at step 92, updates the display 22 with theuser-defined blending factor, as illustrated with image charactercontent where the letter A corresponds to the first medical image 60 andthe letter B corresponds to the second medical image 62. The display 22shows both letters A and B in a blending view based on the user-definedblending factor. At step 94 a, the user begins to adjust the firstwindow/level parameters associated with the first medical image 60 bymoving the mouse cursor 74 into the first window/level control region70. At step 94 b, which occurs simultaneously (or substantiallysimultaneously) with step 94 a, the blending factor synchronizationmodule 38 automatically sets the transparency blending factor 66 to zeroin response to the placement of the mouse cursor 74 within the boundary(or within the vicinity) of the first window/level control region 70.The first medical image 60 becomes fully visible, while the secondmedical image is not visible, which is illustrated with the showing ofonly letter A, not letter B, in the display 22.

At step 96, the user continues to adjust the first window/levelparameters of the first medical image 60 by moving the mouse cursor 74within the boundary of the first window/level control region 70. At step98, the processor 12 of the computer system 10 updates the display 22with updated window/level parameters associated with the first medicalimage 60. At step 100, the user finishes adjusting the firstwindow/level parameters of the first medical image 60. The processor 12resets the transparency blending factor 66 to its initial value,resulting in the showing of letters A and B in the display 22.

After the completion in adjusting the first medical image 60, the userproceeds to adjust the second medical image 62. At step 104 a, the userbegins to adjust the second window/level parameters associated with thesecond medical image 62 by moving the mouse cursor 74 into the secondwindow/level control region 72. At step 104 b, which occurssimultaneously (or substantially simultaneously) with step 104 b, theblending factor synchronization module 38 automatically sets thetransparency blending factor 66 to one in response to the placement ofthe mouse cursor 74 within the boundary (or in the vicinity) of thesecond window/level control region 72. The second medical image 62becomes fully visible, while the first medical image is not visible,which is illustrated with the showing of only letter B, not letter A, inthe display 22.

At step 106, the user continues to adjust the second window/levelparameters of the second medical image 62 by moving the mouse cursor 74within the boundary of the second window/level control region 72. Atstep 108, the processor 12 of the computer system 10 updates the display22 with updated second window/level parameters for the second medicalimage 62. At step 110, the user finishes adjusting the secondwindow/level parameters of the second medical image 62. The processor 12resets the transparency blending factor 66 to its initial value,resulting in the showing of letters A and B in the display 22.

The sequence in the process flow 88 is intended to illustrate oneembodiment, which includes the steps in which the system 10 updates auser-defined blending factor, the system 10 adjusts the firstwindow/level parameters in the first medical image 60, and the system 10adjusts the second window/level parameters in the second medical image62. These three sequences can be altered as an alternative process flow.For example, one alternative process flow is for the system 10 to updatea user-defined blending factor, the system 10 to adjust the secondwindow/level parameters in the second medical image 62, and the system10 to adjust the first window/level parameters in the first medicalimage 60. Another alternative process flow is to place the process stepwhere the system 10 updates a user-defined blending factor between thetwo sequences: the system 10 adjusting the first window/level parametersin the first medical image 60 and the system 10 adjusting the secondwindow/level parameters in the second medical image 62.

In some embodiments, rather than utilizing the blending factorsynchronization module 38 in which the transparency and opaqueness ofthe first image 60 and the second image 62 can be characterized assynchronized, the medical image control engine 36 includes an adjustmentmodule configured to independently change the transparency of each ofthe two medical images 60, 62. The activation of the window/levelcontrols of a first image that is linked to the movement of thetransparency blending factor no longer causes an inverse relationship ina second image. The first image is effectively unsynchronized with thesecond image where the adjustment module is configured to adjust thedegree of transparency (or the degree of opaqueness) of each imageindependently.

FIG. 8 is a flow diagram illustrating the process for executing asynchronized window/level adjustment for multiple images, which in thisinstance can be two or more images. A second aspect of the window/leveladjustment platform as shown in the screen shot 58 in FIG. 3 is appliedto a method for synchronous interactive modification of the window/levelparameters of multiple images—for example, the first medical image 60 isobtained from a CT scanner and the second medical image 62 is obtainedfrom a CBCT scanner. The method of synchronized window/level adjustmentis applicable to any system that displays multiple medical images at thesame time. This approach is not limited to blended views but may alsouse a separate image view, for example, for each image at a differentregion of the display 22. Each image view provides its own control forsetting the window/level parameters of the corresponding image, or twocontrols if the images are presented in a blended view. Whenever theuser interacts with one of the window/level controls 70, 72, not onlyare the parameters of the corresponding single image changing but thoseof all other images as well by using a synchronization mechanism. Allimage views and window/level controls are automatically updatedaccordingly. The synchronization mechanism takes as input thewindow/level parameters of the image the user is currently adjusting andcomputes as output the window/level parameters of a second image, whichshould be updated automatically. If the system 10 displays n images,then n−1 such synchronization mechanisms are required to update allimages synchronously.

At step 114, the user decides whether to adjust the window/levelparameters of the first image 60 or the second image 62. If the userselects to adjust the window/level parameters of the first image 60, theuser adjusts the first window/level parameters of the first image 60 atstep 116. In response to the adjustments to the first window/levelparameters, at step 118, the window/level synchronization module 40 isconfigured to compute automatically the window/level of the second image62. At step 120, the window/level synchronization module 40 isconfigured not only update the display with the updated window/levels ofthe first image 60, but also to propagate automatically the updatedwindow/level parameters of the second image 62 on the same display oranother display. When the user adjusts the window/level of one image,the window/level synchronization module 40 calculates automatically thewindow/level adjustments of other images and synchronizes thewindow/level adjustments of all images. The processor 12 of the computersystem 10 then displays all of the images at the same time based on therespective window/level adjustments.

If the user selects to adjust the window/level parameters of the secondimage 62, at step 122, the user adjusts the second window/levelparameters of the second image 62. In response to the adjustments to thesecond window/level parameters, at step 124, the window/levelsynchronization module 40 is configured to compute automatically thewindow/level of the first image 60. At step 126, the window/levelsynchronization module 40 is configured not only to update the displaywith the updated window/levels of the second image 62, but also topropagate automatically the updated window/level parameters of the firstimage 60 on the same display or another display. When the user adjuststhe window/level of one image, the window/level synchronization module40 calculates automatically the window/level adjustments of other imagesand synchronizes the window/level adjustments of all images. Theprocessor 12 of the computer system 10 then displays all of the imagesat the same time based on the respective window/level adjustments. Sucha synchronization mechanism can operate in various ways, depending onthe type of images corresponding to the input and output imageparameters, which are further described below with respect to FIGS.9A-C.

FIG. 9A is a block diagram illustrating a first embodiment of a generalmapping method for executing a synchronized window/level adjustment formultiple images as described in FIG. 8. In general, the synchronizationmechanism can use any possible mapping between input and outputparameters. This can be implemented by using mathematical expressions orlookup tables, some of which may be constructed empirically. With suchmappings, it becomes possible to synchronize the window/level values oftwo images that have different modalities and/or that are displayedusing different color maps. A mathematical function or algorithm module128 receives an input 130 containing the window/level parametersassociated with the first image 60, processes the window/levelparameters of the first image 60, and generates an output 132 containingthe window/level parameters of the second image 62. Other optional datainputs 134 that may be fed into the mathematical function or algorithmmodule 128 include the pixel data of the first image 60, the pixel dataof the second image 62, the metadata of the first image 60, the metadataof the second image 62, and display characteristics, such as monitoringcalibration data that appears on the display 22. The mathematicalfunction or algorithm module 128 is executed as part of step 118 or 124,as shown in FIG. 8.

FIG. 9B is a block diagram illustrating a second embodiment of apass-through method for executing a synchronized window/level adjustmentfor multiple images as described in FIG. 8. The mechanism copies theinput values and passes them directly to the output, resulting in anoutput 136 having the same data as the input 130. The pass-throughmethod is most suitable if the input and output images are acquired byidentical, calibrated scanners because identical window/level parametersresult in a very similar visual appearance in that case.

FIG. 9C is a block diagram illustrating a third embodiment of ahistogram equalization method for executing a synchronized window/leveladjustment for multiple images as described in FIG. 8. If the two images60, 62 are of the same modality but are generated by scanners fromdifferent manufacturers, the pass-through mechanism might produceunsatisfactory results, in which identical window/level parameters mayproduce a different visual contrast in the display. This is mainlycaused by deviations in the scanner calibration routines and by scatterartifacts in the acquisition. The latter is especially visible if oneimage is acquired by a diagnostic CT scanner and the other one by acone-beam CT scanner. In such situations, histogram equalization canproduce results that are visually more similar. A histogram equalizationalgorithm module 138 is an optimization algorithm that tries to matchthe visual appearance of both displayed images as closely as possible.The histogram equalization algorithm module 138 is configured not onlyto consider the input 130 containing the window/level parametersassociated with the first image 60, but also to take into account asinputs 140 containing the pixel data of the first image 60 and the pixeldata of the second image 60. The histogram equalization algorithm module138 generates an output 142 containing the window/level parameters ofthe second image 62 based on the collective inputs 130, 134.

FIG. 10 is a flow diagram illustrating an exemplary histogramequalization process for executing a synchronized window/leveladjustment for multiple images. At step 130, the window/level inputcomponent 46 in the input module 42 is configured to receive awindow/level of the first image 60. In an initialization step, theprocessor 12 first applies the input window/level parameters to allpixel intensity values of the corresponding input image to compute thedisplay intensity values. The processor 12 initializes the window/levelparameters of the second image 62 at step 144. In parallel steps 146,148, the processor 12 applies the window/level parameters associatedwith the first image to the first image 60, and applies the window/levelparameters associated with the second image to the second image 62. Allresulting values are then accumulated in a histogram which counts foreach possible display intensity the number of image pixels having thatvalue. After initialization, the window/level synchronization module 40is configured to start an optimization loop based on the histogramequalization algorithm 138. Each iteration of that loop chooses a set ofoutput window/level parameters which are applied to the correspondingoutput image to calculate a histogram of its display intensity values.The processor 12 calculates a histogram of display intensities of thefirst image 60 at step 150, and calculates a histogram of displayintensities of the second image 62 at step 152. At step 154, theprocessor 12 compares the first histogram of the first image 60 with thesecond histogram of the second image 62 using a similarity function. Forexample, a suitable similarity function is a modified normalizedcross-correlation. At step 156, the processor 12 determines if the firsthistogram associated with the first image 60 is sufficiently similar tothe second histogram associated with the second image 62. If theprocessor 12 determines that the first histogram is not sufficientlysimilar to the second histogram, the optimization loop 138 is repeatedby adjusting the window/level parameters of the second image 62 at step158 until that function yields a maximum similarity between bothhistograms. Some suitable miniature optimization techniques includeBrute Force, Downhill-Simplex, and Gradient Descent. When the processor12 determines that the first histogram is sufficiently similar to thesecond histogram, the processor 12 generates an output 160 containingthe window/level of the second image 62.

The capabilities described in the various embodiments of the presentinvention to interactively adjust window/level parameters of multipleimages in a blended view and synchronously adjust window/levelparameters of multiple images can assist physicists, oncologists, andcardiologists to diagnose and design a treatment plan for patients. Aradiation oncologist may analyze two medical images where the firstimage was taken by a CT scanner before the patient had developed atumor, and compare it with the second image taken by the CT scannerafter the patient had developed the tumor to analyze the tumorprogression.

The first and second images 60, 62 in the illustrated embodiment arepreferably a first medical image and a second medical image.Alternatively, various formats of the first and second images 60, 62,including two-dimensional (2D) or three-dimensional (3D) images, or 2Dor 3D videos, are applicable to all of the embodiments described in thepresent invention. Note that the histogram equalization has to becomputed globally on the whole N-dimensional image or video and not juston the currently visible part. To phrase it in another way, samplepixels are evenly selected over the whole image spectrum. For speedup onlarge data sets, the histogram equalization may use a deterministic orrandom subset of the pixels as long as it is distributed evenly over thewhole data set.

In some embodiments with 3D images or videos, the display can be one ormore 2D slice views or 3D volume renderings or a combination of both.Embodiments of the methods can be applied to multi-channel images/videosthat store more than one intensity value per pixel, for example RGBtriplets. In some embodiments, the output does not have to usegray-scale intensities where the methods may also use various colormaps. The methods can be applied to any high-dynamic range images orvideos, not necessarily from the medical field, such as from aphotography field.

In some embodiments, one of the first and second medical images 60, 62comprises an expert case. For example, an expert case is adisease-matched expert case with a set of target volume contours thatprovide outlines of different CT images for radiotherapy treatment. Thefirst medical image 60 can be supplied from an expert case through auser interface, which provides an expert contour, and the expert contouris overlaid with the second medical image 62 that includes a patientimage. For additional information on some, most, or all of the functionsof a method relating to the selection of a set of target volume contoursbased of a disease-matched expert case, see U.S. Pat. No. 7,995,813entitled “Reducing Variation in Radiation Treatment Therapy Planning,”owned by the assignee of this application and incorporated by referenceas if fully set forth herein.

FIG. 11 is a block diagram illustrating the second system embodiment ofa cloud computing environment 162 accessible by cloud clients 164 for aphysician to view and adjust window/level parameters of multiple imagedisplays. A cloud computer 166 running a cloud operating system 176,which may include other additional cloud computers, for datacommunications. The cloud clients 164 communicate with the cloudcomputer 166 through the network 30, either wirelessly by via a wiredconnection. The cloud clients 164 are broadly defined to include, butnot limited to, desktop computers, mobile devices, notebook computers,SmartTVs, and SmartAutos. A variety of mobile devices are applicable tothe present invention including mobile phones, smartphones like iPhones,tablet computers like iPads, and browser-based notebook computers likeChromebooks, with a processor, a memory, a screen, with connectioncapabilities of Wireless Local Area Network (WLAN) and Wide Area Network(WAN). The mobile device is configured with a full or partial operatingsystem (OS) software which provides a platform for running basic andadvanced software applications. The mobile device functioning as thecloud client 164 accesses the cloud computer 166 through a web browser.

In this embodiment, the cloud computer 166 (also referred to as aweb/HTTP server) comprises a processor 168, an authentication module170, a virtual storage of medical images 172, a RAM 174 for executing acloud operating system 176, virtual clients 178, and the medical imagecontrol engine 36. The cloud operating system 176 can be implemented asa module of automated computing machinery installed and operating on oneof the cloud computers. In some embodiments, the cloud operating system176 can include several submodules for providing its intended functionalfeatures, such as the virtual clients 178, the medical image controlengine 36, and the virtual storage 172.

In an alternate embodiment, the authentication module 170 can beimplemented as an authentication server. The authentication module 170is configured to authenticate, and grant permission, whether the cloudclient 164 is an authorized user to access one or more medical imagesassociated with a particular patient in the virtual storage 180. Theauthentication server 30 may employ a variety of authenticationprotocols to authenticate the user, such as a Transport Layer Security(TLS) or Secure Socket Layer (SSL), which are cryptographic protocolsthat provide security for communications over networks like theInternet.

Medical images, which include the first medical image 60 and the secondmedical image 62, can be stored in the virtual storage 180 of the cloudcomputer 166 in the cloud computing environment 162. The cloud client162, such as a smartphone or a tablet computer, is capable of accessingthe virtual storage 180 in the cloud computer 166 through the network 30and displays medical images on the display of the cloud client 162. Aphysician would be able to view, and adjust, the medical images from aremote location on a handheld device.

In one embodiment, the cloud computer 166 is a browser-based operatingsystem communicating through an Internet-based computing network thatinvolves the provision of dynamically scalable and often virtualizedresources as a service over the Internet, such as iCloud@ available fromApple Inc. of Cupertino, Calif., Amazon Web Services (IaaS) and ElasticCompute Cloud (EC2) available from Amazon.com, Inc. of Seattle, Wash.,SaaS and PaaS available from Google Inc. of Mountain View, Calif.,Microsoft Azure Service Platform (PAAS) available from MicrosoftCorporation of Redmond, Wash., Sun Open Cloud Platform available fromOracle Corporation of Redwood City, Calif., and other cloud computingservice providers.

The web browser is a software application for retrieving, presenting,and traversing a Uniform Resource Identifier (URI) on the World Wide Webprovided by the cloud computer 166 or web servers. One common type ofURI begins with Hypertext Transfer Protocol (HTTP) and identifies aresource to be retrieved over the HTTP. A web browser may include, butis not limited to, browsers running on personal computer operatingsystems and browsers running on mobile phone platforms. The first typeof web browsers may include Microsoft's Internet Explorer, Apple'sSafari, Google's Chrome, and Mozilla's Firefox. The second type of webbrowsers may include the iPhone OS, Google Android, Nokia S60 and PalmWebOS. Examples of a URI include a web page, an image, a video, or othertype of content.

The network 30 can be implemented as a wireless network, a wired networkprotocol or any suitable communication protocols, such as 3G (3rdgeneration mobile telecommunications), 4G (fourth-generation of cellularwireless standards), long term evolution (LTE), 5G, a wide area network(WAN), Wi-Fi™ like wireless local area network (WLAN) 802.11n, or alocal area network (LAN) connection (internetwork—connected to eitherWAN or LAN), Ethernet, Bluebooth™, high frequency systems (e.g., 900MHz, 2.4 GHz, and 5.6 GHz communication systems), infrared, transmissioncontrol protocol/internet protocol (“TCP/IP”) (e.g., any of theprotocols used in each of the TCP/IP layers), hypertext transferprotocol (“HTTP”), BitTorrent™, file transfer protocol (“FTP”),real-time transport protocol (“RTP”), real-time streaming protocol(“RTSP”), secure shell protocol (“SSH”), any other communicationsprotocol and other types of networks like a satellite, a cable network,or an optical network set-top boxes (STBs).

A SmartAuto includes an auto vehicle with a processor, a memory, ascreen, with connection capabilities of Wireless Local Area Network(WLAN) and Wide Area Network (WAN), or an auto vehicle with atelecommunication slot connectable to a mobile device like iPods,iPhones, and iPads.

A SmartTV includes a television system having a telecommunication mediumfor transmitting and receiving moving video images (either monochromaticor color), still images and sound. The television system operates as atelevision, a computer, an entertainment center, and a storage device.The telecommunication medium of the television system includes atelevision set, television programming, television transmission, cableprogramming, cable transmission, satellite programming, satellitetransmission, Internet programming, and Internet transmission.

Some portions of the above description describe the embodiments in termsof algorithmic descriptions and processes, e.g. as with the descriptionwithin FIGS. 1-11. These operations (e.g., the processes describedabove), while described functionally, computationally, or logically, areunderstood to be implemented by computer programs or equivalentelectrical circuits, microcode, or the like. The computer programs aretypically embedded as instructions that can be stored on a tangiblecomputer readable storage medium (e.g., flash drive disk, or memory) andare executable by a processor, for example, as described in FIGS. 1-11.Furthermore, it has also proven convenient at times to refer to thesearrangements of operations as modules, without loss of generality. Theoperations described and their associated modules may be embodied insoftware, firmware, hardware, or any combinations thereof.

As used herein any reference to “one embodiment” or “an embodiment”means that a particular element, feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment.

Some embodiments may be described using the expression “coupled” and“connected” along with their derivatives. It should be understood thatthese terms are not intended as synonyms for each other. For example,some embodiments may be described using the term “connected” to indicatethat two or more elements are in direct physical or electrical contactwith each other. In another example, some embodiments may be describedusing the term “coupled” to indicate that two or more elements are indirect physical or electrical contact. The term “coupled,” however, mayalso mean that two or more elements are not in direct contact with eachother, but yet still cooperate or interact with each other. Theembodiments are not limited in this context.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having,” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to “an inclusive or” and “not to an exclusive or”. Forexample, a condition A or B is satisfied by any one of the following: Ais true (or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

The terms “a” or “an,” as used herein, are defined as one or more thanone. The term “plurality,” as used herein, is defined as two or morethan two. The term “another,” as used herein, is defined as at least asecond or more.

The invention can be implemented in numerous ways, including as aprocess, an apparatus, and a system. In this specification, theseimplementations, or any other form that the invention may take, may bereferred to as techniques. In general, the order of the connections ofdisclosed apparatus may be altered within the scope of the invention.

The present invention has been described in particular detail withrespect to one possible embodiment. Those skilled in the art willappreciate that the invention may be practiced in other embodiments.First, the particular naming of the components, capitalization of terms,the attributes, data structures, or any other programming or structuralaspect is not mandatory or significant, and the mechanisms thatimplement the invention or its features may have different names,formats, or protocols. Further, the system may be implemented via acombination of hardware and software, as described, or entirely inhardware elements. Also, the particular division of functionalitybetween the various system components described herein is merelyexemplary, and not mandatory; functions performed by a single systemcomponent may instead be performed by multiple components, and functionsperformed by multiple components may instead be performed by a singlecomponent.

An ordinary artisan should require no additional explanation indeveloping the methods and systems described herein but may neverthelessfind some possibly helpful guidance in the preparation of these methodsand systems by examining standard reference works in the relevant art.

These and other changes can be made to the invention in light of theabove detailed description. In general, in the following claims, theterms used should not be construed to limit the invention to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all methods and systems that operateunder the claims set forth herein below. Accordingly, the invention isnot limited by the disclosure, but instead its scope is to be determinedentirely by the following claims.

What is claimed is:
 1. A method comprising: presenting, by a processor,a user interface having a first gradual level selector, a second graduallevel selector, and a third gradual level selector; presenting, by theprocessor, a first volume rendering image and a second volume renderingimage concurrently in the user interface such the first volume renderingimage overlays the second volume rendering image, wherein the firstvolume rendering image has a first window parameter and a first levelparameter, wherein the second volume rendering image has a second windowparameter and a second level parameter; setting, by the processor, thefirst gradual level selector to control the first window parameter andthe first level parameter of the first volume rendering image, thesecond gradual level selector to control the second window parameter andthe second level parameter, and the third gradual level selector tocontrol a degree of transparency of the first volume rendering image andthe second volume rendering image between a first point and a secondpoint; adjusting, by the processor, the third gradual level selectorsuch that the first volume rendering image is shown and the secondvolume rendering image is not shown when the third gradual levelselector is at the first point, the second volume rendering image isshown and the first volume rendering image is not shown when the thirdgradual level selector is at the second point, and the first volumerendering image and the second image are shown and are identical in thedegree of transparency when the third gradual level selector is medialrelative to the first point and the second point; linking, by theprocessor, each of the first gradual level selector and the secondgradual level selector to the third gradual level selector such that thethird gradual level selector is adjusted proportionally between thefirst point and the second point inclusively and the first volumerendering image or the second volume rendering image becomes opaque ortransparent when a user input causes movement of the first gradual levelselector or the second gradual level selector respectively; andchanging, by the processor, a plurality of window parameters and aplurality of level parameters of a plurality of volume rendering imagesexclusive of the first volume rendering image and the second volumerendering image based on the first window parameter and the first levelparameter or the second window parameter and the second level parameterbeing changed, wherein the plurality of volume rendering images arerelated to the first volume rendering image or the second volumerendering image.
 2. The method of claim 1, wherein the first graduallevel selector opposes the second gradual level selector such that thefirst volume rendering image and the second volume rendering image arepresented between the first gradual level selector and the secondgradual level selector.
 3. The method of claim 2, wherein the thirdgradual level selector is positioned between the first gradual levelselector and the second gradual level selector.
 4. The method of claim1, wherein the input involves a cursor, wherein the first volumerendering image or the second volume rendering image has a region,wherein the region becomes more transparent and a zooming factorincreases simultaneously thereby resulting in a higher transparent andclose-up view of the first volume rendering image or the second volumerendering image when the cursor controls the first gradual levelselector or the second gradual level selector associated with theregion.
 5. The method of claim 1, wherein the first point is a lowerbound on a sliding scale and the second point is an upper bound on thesliding scale.
 6. The method of claim 1, wherein the first volumerendering image and the second volume rendering image are sourced from amedical image scanner.
 7. The method of claim 6, wherein the firstvolume rendering image and the second volume rendering image depict anobject in a position, and further comprising: identifying, by theprocessor, a deviation between the first volume rendering image and thesecond volume rendering image such that the position can be adjustedbased on a predetermined plan involving the medical image scanner. 8.The method of claim 1, further comprising: presenting, by the processor,the plurality of volume rendering images concurrently based on thewindow parameters and the level parameters being changed.
 9. The methodof claim 8, wherein the plurality of volume rendering images arepresented side-by-side to visualize a progression of a condition overtime.
 10. A system comprising: a processor, a memory, a display, and auser input device, wherein the processor is in communication with thememory, the display, and the user input device, wherein the memorystores a set of instructions that executable configures the processorto: present a user interface having a first gradual level selector, asecond gradual level selector, and a third gradual level selector,wherein the user interface is presented on the display; present a firstvolume rendering image and a second volume rendering image concurrentlyin the user interface such the first volume rendering image overlays thesecond volume rendering image, wherein the first volume rendering imagehas a first window parameter and a first level parameter, wherein thesecond volume rendering image has a second window parameter and a secondlevel parameter; set the first gradual level selector to control thefirst window parameter and the first level parameter of the first volumerendering image, the second gradual level selector to control the secondwindow parameter and the second level parameter, and the third graduallevel selector to control a degree of transparency of the first volumerendering image and the second volume rendering image between a firstpoint and a second point; adjust the third gradual level selector suchthat the first volume rendering image is shown and the second volumerendering image is not shown when the third gradual level selector is atthe first point, the second volume rendering image is shown and thefirst volume rendering image is not shown when the third gradual levelselector is at the second point, and the first volume rendering imageand the second image are shown and are identical in the degree oftransparency when the third gradual level selector is medial relative tothe first point and the second point; link each of the first graduallevel selector and the second gradual level selector to the thirdgradual level selector such that the third gradual level selector isadjusted proportionally between the first point and the second pointinclusively and the first volume rendering image or the second volumerendering image becomes opaque or transparent when a user input causesmovement of the first gradual level selector or the second gradual levelselector respectively and; change a plurality of window parameters and aplurality of level parameters of a plurality of volume rendering imagesexclusive of the first volume rendering image and the second volumerendering image based on the first window parameter and the first levelparameter or the second window parameter and the second level parameterbeing changed, wherein the plurality of volume rendering images arerelated to the first volume rendering image or the second volumerendering image.
 11. The system of claim 10, wherein the first graduallevel selector opposes the second gradual level selector such that thefirst volume rendering image and the second volume rendering image arepresented between the first gradual level selector and the secondgradual level selector.
 12. The system of claim 11, wherein the thirdgradual level selector is positioned between the first gradual levelselector and the second gradual level selector.
 13. The system of claim10 wherein the input involves a cursor, wherein the first volumerendering image or the second volume rendering image has a region,wherein the region becomes more transparent and a zooming factorincreases simultaneously thereby resulting in a higher transparent andclose-up view of the first volume rendering image or the second volumerendering image when the cursor controls the first gradual levelselector or the second gradual level selector associated with theregion.
 14. The system of claim 10, wherein the first point is a lowerbound on a sliding scale and the second point is an upper bound on thesliding scale.
 15. The system of claim 10, wherein the first volumerendering image and the second volume rendering image are sourced from amedical image scanner.
 16. The system of claim 15, wherein the firstvolume rendering image and the second volume rendering image depict anobject in a position, and the set of instructions executable configuresthe processor to: identify a deviation between the first volumerendering image and the second volume rendering image such that theposition can be adjusted based on a predetermined plan involving themedical image scanner.
 17. The system of claim 10, wherein the set ofinstructions executable configures the processor to: present theplurality of volume rendering images concurrently based on the windowparameters and the level parameters being changed.
 18. The system ofclaim 17, wherein the plurality of volume rendering images are presentedside-by-side to visualize a progression of a condition over time.